Arylsulfur pentafluorides compounds are used to introduce one or more sulfur pentafluoride groups into various commercial organic molecules. In particular, arylsulfur pentafluorides have been shown as useful compounds (as product or intermediate) in the development of liquid crystals, in bioactive chemicals such as fungicides, herbicides, and insecticides, and in other like materials [see Fluorine-containing Synthons (ACS Symposium Series 911), ed by V. A. Soloshonok, American Chemical Society (2005), pp. 108-113]. However, as discussed herein, conventional synthetic methodologies to produce arylsulfur pentafluorides have proven difficult and are a concern within the art.
Generally, arylsulfur pentafluorides are synthesized using one of the following synthetic methods: (1) fluorination of diaryl disulfides or arylsulfur trifluoride with AgF2 [see J. Am. Chem. Soc., Vol. 84 (1962), pp. 3064-3072, and J. Fluorine Chem. Vol. 112 (2001), pp. 287-295]; (2) fluorination of di(nitrophenyl)disulfides, nitrobenzenethiols, or nitrophenylsulfur trifluorides with molecular fluorine (F2) [see Tetrahedron, Vol. 56 (2000), pp. 3399-3408; Eur. J. Org. Chem., Vol. 2005, pp. 3095-3100; and U.S. Pat. No. 5,741,935]; (3) fluorination of diaryl disulfides or arenethiols with F2, CF3OF, or CF2(OF)2 in the presence or absence of a fluoride source (see US Patent Publication No. 2004/0249209 A1); (4) fluorination of diaryl disulfides with XeF2 [see J. Fluorine Chem., Vol. 101 (2000), pp. 279-283]; (5) reaction of 1,4-bis(acetoxy)-2-cyclohexene with SF5Br followed by dehydrobromination or hydrolysis and then aromatization reactions [see J. Fluorine Chem., Vol. 125 (2004), pp. 549-552]; (6) reaction of 4,5-dichloro-1-cyclohexene with SF5Cl followed by dehydrochlorination [see Organic Letters, Vol. 6 (2004), pp. 2417-2419 and PCT WO 2004/011422 A1]; and (7) reaction of SF5Cl with acetylene, followed by bromination, dehydrobromination, and reduction with zinc, giving pentafluorosulfanylacetylene, which was then reacted with butadiene, followed by an aromatization reaction at very high temperature [see J. Org. Chem., Vol. 29 (1964), pp. 3567-3570].
Each of the above synthetic methods has one or more drawbacks making it either impractical (time or yield), overly expensive, and/or overly dangerous to practice. For example, synthesis methods (1) and (4) provide low yields and require expensive reaction agents, e.g., AgF2 and XeF2. Methods (2) and (3) require the use of F2, CF3OF, or CF2(OF)2, each of which is toxic, explosive, and corrosive, and products produced using these methods are at a relatively low yield. Note that handling of these gasses is expensive from the standpoint of the gasses production, storage and use. In addition, synthesis methods that require the use of F2, CF3OF, and/or CF2(OF)2 are limited to the production of deactivated arylsulfur pentafluorides, such as nitrophenylsulfur pentafluorides, due to their extreme reactivity, which leads to side-reactions such as fluorination of the aromatic rings when not deactivated. Methods (5) and (6) also require expensive reactants, e.g., SF5Cl or SF5Br, and have narrow application because the starting cyclohexene derivatives are limited. Finally, method (7) requires the expensive reactant SF5Cl and includes many reaction steps to reach the arylsulfur pentafluorides (timely and low yield). Therefore, problems with the production methods for arylsulfur pentafluorides have made it difficult to prepare the material in a safe, cost effective and timely fashion.
Phenylsulfur chlorotetrafluoride, p-methylphenylsulfur chlorotetrafluoride, and p-nitrophenylsulfur chlorotetrafluoride were detected in the reaction of diphenyl disulfide, bis(p-methylphenyl)disulfide, and bis(p-nitrophenyl)disulfide, respectively, with XeF2 in the presence of tetraethylammonium chloride (see Can. J. Chem., Vol. 75, pp. 1878-1884). Chemical structures of the chlorotetrafluoride compounds were assigned by analysis of the NMR data of the reaction mixtures, but these compounds were not isolated. Therefore, the physical properties of the chlorotetrafluorides were unknown. This synthesis method using XeF2 was industrially impractical because XeF2 is overly expensive for large scale production.
The present invention is directed toward overcoming one or more of the problems discussed above.